/*
 * Copyright 2004 original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.mvc.component.file.service;

import java.io.File;
import java.util.Properties;

import org.apache.commons.lang.StringUtils;

public final class FileMimeUtils {

	private FileMimeUtils() {

	}
	/**
	 * MIMETYPES_PROPERTIES
	 */
	public static final String MIMETYPES_PROPERTIES = "mimeTypes.properties";
	private static Properties properties;

	/**
	 * Return the mime type for a file. The extension is parsed out and the
	 * method to get mime type by extension is called. Extension mappings are
	 * found in the mimeTypes.properties file in the org.extremecomponents.util
	 * package.
	 */
	public static String getFileMimeType(File file) {
		if (file == null) {
			return null;
		}

		return getFileMimeType(file.getName());
	}

	/**
	 * Return the mime type for a file name. The extension is parsed out and the
	 * method to get mime type by extension is called. Extension mappings are
	 * found in the mimeTypes.properties file in the org.extremecomponents.util
	 * package.
	 */
	public static String getFileMimeType(String fileName) {
		if (StringUtils.isBlank(fileName) || (fileName.indexOf(".") == -1)) {
			return null;
		}

		fileName = fileName.substring(fileName.lastIndexOf("."));

		return getExtensionMimeType(fileName);
	}

	/**
	 * Return the mime type for a given extension. Extensions can include the
	 * dot or just be the extension without the dot. Extension mappings are
	 * found in the mimeTypes.properties file in the org.extremecomponents.util
	 * package.
	 */
	public static String getExtensionMimeType(String extension) {
		String result = null;
		if (StringUtils.isBlank(extension)) {
			return result;
		}
		extension = extension.toLowerCase();
		if (!extension.startsWith(".")) {
			extension = "." + extension;
		}
		result = (String) properties.get(extension);
		return result;
	}

	static {
		try {
			properties = new Properties();
			properties.load(Thread.currentThread().getContextClassLoader().getResourceAsStream(MIMETYPES_PROPERTIES));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * Just a test harness.
	 */
	public static void main(String[] args) {
		System.out.println("MimeUtils.getExtensionMimeType(.gif)=" + FileMimeUtils.getExtensionMimeType(".gif"));
		System.out.println("MimeUtils.getExtensionMimeType(.pdf)=" + FileMimeUtils.getExtensionMimeType(".pdf"));
		System.out.println("MimeUtils.getExtensionMimeType(.xls)=" + FileMimeUtils.getExtensionMimeType(".xls"));
		System.out.println("MimeUtils.getFileMimeType(foo.gif)=" + FileMimeUtils.getFileMimeType("foo.gif"));
		System.out.println("MimeUtils.getFileMimeType(foo.pdf)=" + FileMimeUtils.getFileMimeType("foo.pdf"));
		System.out.println("MimeUtils.getFileMimeType(foo.xls)=" + FileMimeUtils.getFileMimeType("foo.xls"));
		System.out.println("MimeUtils.getFileMimeType(foo.badextension)="
		        + FileMimeUtils.getFileMimeType("foo.badextension"));
	}
}
